Hi Jeff, I had looked at Pozar... My confusion is that at 5.94 GHz the line is many many quarter wavelengths long. I don't see why 5.94 GHz ends up being the frequency it resonates at. Any thoughts? -Jason -----Original Message----- From: Loyer, Jeff [mailto:jeff.loyer@xxxxxxxxx] Sent: Tuesday, November 15, 2005 10:19 AM To: pritchard_jason@xxxxxxx; SI List Subject: RE: [SI-LIST] Single ended s-parameters of a differential mircostrip line The best reference I know of for analyzing this phenomena is Pozar's "Microwave Engineering", pages 389 ("coupled line couplers") & 475 ("coupled line filters"). Jeff Loyer -----Original Message----- From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] On Behalf Of pritchard, jason Sent: Tuesday, November 15, 2005 6:50 AM To: SI List Subject: [SI-LIST] Single ended s-parameters of a differential mircostrip line Hi All, I have a Differential Microstrip line with the parameters below. If you were to look at the Single ended s-parameters for a 12 inch line you will see it resonate at 5.94 GHz and 11.9 Ghz for a 6 inch line etc.... Given these parameters how do you calculate the point at which the single ended s-parameters will resonate? I know it's a function of the length and the coupling to the other line because you don't see this effect with a single trace. I just don't know the mathematical relationship. Thanks, Jason * Units are per inch +Co = + 2.539e-12 + -2.498e-13 2.539e-12 +Lo = + 8.362e-09 + 1.227e-09 8.362e-09 +Gd = + 3.173e-13 + -2.341e-14 3.173e-13 +Ro = + 7.145e-02 + 0.000e+00 7.145e-02 +Rs = + 3.196e-05 + 1.365e-06 3.196e-05 ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: //www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List FAQ wiki page is located at: http://si-list.org/wiki/wiki.pl?Si-List_FAQ List technical documents are available at: http://www.si-list.org List archives are viewable at: //www.freelists.org/archives/si-list or at our remote archives: http://groups.yahoo.com/group/si-list/messages Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: //www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List FAQ wiki page is located at: http://si-list.org/wiki/wiki.pl?Si-List_FAQ List technical documents are available at: http://www.si-list.org List archives are viewable at: //www.freelists.org/archives/si-list or at our remote archives: http://groups.yahoo.com/group/si-list/messages Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu